考虑圆柱铰链间隙的多刚体系统动力学计算方法

为了研究含圆柱铰链间隙的多刚体系统动力学计算方法，针对三维圆柱铰链的结构特点，给出了一种改进的接触对确定方法，构造了空间间隙圆柱铰链接触分离切换点的判别方法。法向接触力采用Lankarani与Nikravesh的连续接触力模型计算，切向摩擦力采用修正的Coulomb模型计算，综合考虑接触分离状态建立了统一形式的动力学方程。最后对比间隙铰链机构和理想铰链机构运动，结果表明圆柱铰链间隙在短时间内对其他构件的运动影响很小，但严重增大了铰链内部的碰撞力，长时间运动后机构的位移、速度、加速度与理想铰链偏差变大，但接触摩擦力使圆柱铰链的轴向运动受到抑制。间隙圆柱铰链的研究方法和结果为相关和更复杂的含间隙圆柱铰链机构的运动分析提供了理论参考。

Computational method of rigid multibody system dynamics with cylindrical joint clearance

A dynamical model for multi-body system dynamics with cylindrical joint clearance was studied. An improved method for detecting potential contact points and the technique for deciding contact and separation were established based on the joint’s structural features. The normal contact force was modeled using the continuous approach proposed by Lankarani and Nikravesh, and the tangent friction was calculated using a modified Coulomb’s friction law. A unified dynamic equation of the multi-body system was established considering “contact” and “separation” scenarios. The numerical analysis of a mechanism with joint clearance indicate that joint clearance has little effect upon other part’s movements and causes high contact-impact forces in a short period of time. As time increases, other parts are seriously affected by the joint clearance. However, axle movements of the contacted parts are influenced by the contact friction. Furthermore, the presented method offers the theory reference for related and more complex mechanisms.